The disconnect between what we know and what we think we know forms the crux of Married Life, a smart little cinematic cocktail that is one jigger domestic melodrama, one jigger film noir and two jiggers smooth dark comedy. Based on a 1953 pulp novel by John Bingham, the film wrings pathos and humor from its deeply flawed people, yet writer-director Ira Sachs is not cruel to his characters. They mean to do the right thing; they want to be true to their convictions. It's just that they don't have a clue about what that entails.

Harry Allen (Chris Cooper) and Richard Langley (Pierce Brosnan) are good friends who meet one afternoon for lunch. At first blush, the two seem to be unlikely chums. The bespectacled Harry is married, serious-minded and a bit on the dour side. By contrast, the silky Richard is a confirmed bachelor who equates marriage with the flu.

Harry opens up to his friend. All is not well, he says, with his marriage to the dutiful Pat (Patricia Clarkson). Harry reveals that Pat views love as sex, while he, Harry, yearns for something more, a deep and abiding connection. "You can't have everything, Harry," quips Richard. Then Harry drops his bombshell: He is going to leave Pat. Harry is deeply in love and having an affair with a luminous young widow named Kay Nesbitt (Rachel McAdams). This being 1949, the friends' heart-to-heart talk is accompanied by martinis.

Then Kay shows up to join the pair for lunch. Richard, who also serves as voiceover narrator, is immediately smitten with the platinum blonde and resolves to woo the beauty away from his best friend.

Harry is oblivious to such shenanigans, however, instead preoccupied about how he can possibly divorce Pat without devastating her. Surely, he reasons, this loyal and loving mate deserves better. An idea comes to him when he picks up a hitchhiker (Timothy Webber) who mentions that his sister recently died after a lengthy illness. The hitchhiker calls the passing "blessed release" for the sister.

Something about the concept clicks with Harry, who convinces himself the only loving recourse is to stop Pat's heart before he can break it.

One of the wicked joys of Married Life is how its principal characters straddle lines between selfishness and selflessness. Harry is sincere in his belief that killing Pat is the most loving way to let her go. Pat, it must be said, has her own perverse ideas about fealty. The story's most virtuous character -- certainly its most clear-eyed -- might just be Richard, and he betrays his best friend. Despite such bad behavior, however, the film finds everyone has their reasons.

Sachs, who co-wrote the script with Owen Moverman, allows the story to unfold with cool precision. He does not batter viewers over the head. Married Life is not slow-paced, but neither does it rush, its tone flitting seamlessly from suspense to black comedy to straightforward drama. It is a balancing act that Sachs executes with seemingly effortless skill.

The acting is superb. Cooper, craggy-faced and eyes puffy, burrows inside the ambivalence of Harry, a man who endures great psychological pain but doles out a fair amount of it himself. Clarkson is excellent as always, while Brosnan continues his revelatory post-Bond career.

Presented in anamorphic widescreen 1.85:1, Married Life boasts sparkling picture quality, full of crisp details and a vibrant scheme. Minor grain is evident in a few dimly lighted scenes.

The Dolby Digital 5.1 mix is first-rate. Dialogue is clear and clean, with no noticeable distortion or drop-out. Disappointingly, the disc's only subtitle option is English.

Sachs contributes a smart and informative commentary. There are some inevitable dead patches -- he could have used someone to interact with -- but he proves to be a storyteller of uncommon complexity. There is considerable discussion of Married Life's thematic concerns.

Three alternate endings have a combined running time of 20 minutes, 42 seconds. Admirers of the film will find this worthwhile viewing, especially since what made the final cut is so radically different in tone. The original endings revolve around a 16-year flash forward. It's reasonably compelling stuff, but McAdams' Kay is eerily unfettered by aging. The scenes, which can be watched separately or consecutively, include optional commentary by Sachs.

Rounding things out are a theatrical trailer and a handful of previews.

Married Life is a noir thriller, black comedy, wry satire and poignant melodrama. Most interestingly, it accomplishes all of this without feeling schizophrenic. After a nominal theatrical release, this absorbing, caustic and ultimately compassionate motion picture deserves a second life on DVD.